Hi everyone, I am trying to build a Lab Bench Power Supply out of old computer PSU and I am seeing that some guys are using a dummy load resistor on output so I want to know whats their use and is it necessary to use them ?

thanks,

 

Some power supplies need one to work but most newer supplies dont. If your voltage comes up you don't need one if no voltage comes up try one.

 

The usual resistor used is a 10 ohm 10 watt on the 5 volt supply, it's used to help stabilize the supply.